contrib/libvhost-user/libvhost-user.h

   1 /*
   2  * Vhost User library
   3  *
   4  * Copyright (c) 2016 Red Hat, Inc.
   5  *
   6  * Authors:
   7  *  Victor Kaplansky <victork@redhat.com>
   8  *  Marc-André Lureau <mlureau@redhat.com>
   9  *
  10  * This work is licensed under the terms of the GNU GPL, version 2 or
  11  * later.  See the COPYING file in the top-level directory.
  12  */
  13
  14 #ifndef LIBVHOST_USER_H
  15 #define LIBVHOST_USER_H
  16
  17 #include <stdint.h>
  18 #include <stdbool.h>
  19 #include <stddef.h>
  20 #include <sys/poll.h>
  21 #include <linux/vhost.h>
  22 #include "standard-headers/linux/virtio_ring.h"
  23
  24 /* Based on qemu/hw/virtio/vhost-user.c */
  25 #define VHOST_USER_F_PROTOCOL_FEATURES 30
  26 #define VHOST_LOG_PAGE 4096
  27
  28 #define VHOST_MAX_NR_VIRTQUEUE 8
  29 #define VIRTQUEUE_MAX_SIZE 1024
  30
  31 #define VHOST_MEMORY_MAX_NREGIONS 8
  32
  33 typedef enum VhostSetConfigType {
  34     VHOST_SET_CONFIG_TYPE_MASTER = 0,
  35     VHOST_SET_CONFIG_TYPE_MIGRATION = 1,
  36 } VhostSetConfigType;
  37
  38 /*
  39  * Maximum size of virtio device config space
  40  */
  41 #define VHOST_USER_MAX_CONFIG_SIZE 256
  42
  43 enum VhostUserProtocolFeature {
  44     VHOST_USER_PROTOCOL_F_MQ = 0,
  45     VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1,
  46     VHOST_USER_PROTOCOL_F_RARP = 2,
  47     VHOST_USER_PROTOCOL_F_REPLY_ACK = 3,
  48     VHOST_USER_PROTOCOL_F_NET_MTU = 4,
  49     VHOST_USER_PROTOCOL_F_SLAVE_REQ = 5,
  50     VHOST_USER_PROTOCOL_F_CROSS_ENDIAN = 6,
  51     VHOST_USER_PROTOCOL_F_CRYPTO_SESSION = 7,
  52     VHOST_USER_PROTOCOL_F_PAGEFAULT = 8,
  53     VHOST_USER_PROTOCOL_F_CONFIG = 9,
  54     VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD = 10,
  55     VHOST_USER_PROTOCOL_F_HOST_NOTIFIER = 11,
  56     VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD = 12,
  57
  58     VHOST_USER_PROTOCOL_F_MAX
  59 };
  60
  61 #define VHOST_USER_PROTOCOL_FEATURE_MASK ((1 << VHOST_USER_PROTOCOL_F_MAX) - 1)
  62
  63 typedef enum VhostUserRequest {
  64     VHOST_USER_NONE = 0,
  65     VHOST_USER_GET_FEATURES = 1,
  66     VHOST_USER_SET_FEATURES = 2,
  67     VHOST_USER_SET_OWNER = 3,
  68     VHOST_USER_RESET_OWNER = 4,
  69     VHOST_USER_SET_MEM_TABLE = 5,
  70     VHOST_USER_SET_LOG_BASE = 6,
  71     VHOST_USER_SET_LOG_FD = 7,
  72     VHOST_USER_SET_VRING_NUM = 8,
  73     VHOST_USER_SET_VRING_ADDR = 9,
  74     VHOST_USER_SET_VRING_BASE = 10,
  75     VHOST_USER_GET_VRING_BASE = 11,
  76     VHOST_USER_SET_VRING_KICK = 12,
  77     VHOST_USER_SET_VRING_CALL = 13,
  78     VHOST_USER_SET_VRING_ERR = 14,
  79     VHOST_USER_GET_PROTOCOL_FEATURES = 15,
  80     VHOST_USER_SET_PROTOCOL_FEATURES = 16,
  81     VHOST_USER_GET_QUEUE_NUM = 17,
  82     VHOST_USER_SET_VRING_ENABLE = 18,
  83     VHOST_USER_SEND_RARP = 19,
  84     VHOST_USER_NET_SET_MTU = 20,
  85     VHOST_USER_SET_SLAVE_REQ_FD = 21,
  86     VHOST_USER_IOTLB_MSG = 22,
  87     VHOST_USER_SET_VRING_ENDIAN = 23,
  88     VHOST_USER_GET_CONFIG = 24,
  89     VHOST_USER_SET_CONFIG = 25,
  90     VHOST_USER_CREATE_CRYPTO_SESSION = 26,
  91     VHOST_USER_CLOSE_CRYPTO_SESSION = 27,
  92     VHOST_USER_POSTCOPY_ADVISE  = 28,
  93     VHOST_USER_POSTCOPY_LISTEN  = 29,
  94     VHOST_USER_POSTCOPY_END     = 30,
  95     VHOST_USER_GET_INFLIGHT_FD = 31,
  96     VHOST_USER_SET_INFLIGHT_FD = 32,
  97     VHOST_USER_MAX
  98 } VhostUserRequest;
  99
 100 typedef enum VhostUserSlaveRequest {
 101     VHOST_USER_SLAVE_NONE = 0,
 102     VHOST_USER_SLAVE_IOTLB_MSG = 1,
 103     VHOST_USER_SLAVE_CONFIG_CHANGE_MSG = 2,
 104     VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG = 3,
 105     VHOST_USER_SLAVE_MAX
 106 }  VhostUserSlaveRequest;
 107
 108 typedef struct VhostUserMemoryRegion {
 109     uint64_t guest_phys_addr;
 110     uint64_t memory_size;
 111     uint64_t userspace_addr;
 112     uint64_t mmap_offset;
 113 } VhostUserMemoryRegion;
 114
 115 typedef struct VhostUserMemory {
 116     uint32_t nregions;
 117     uint32_t padding;
 118     VhostUserMemoryRegion regions[VHOST_MEMORY_MAX_NREGIONS];
 119 } VhostUserMemory;
 120
 121 typedef struct VhostUserLog {
 122     uint64_t mmap_size;
 123     uint64_t mmap_offset;
 124 } VhostUserLog;
 125
 126 typedef struct VhostUserConfig {
 127     uint32_t offset;
 128     uint32_t size;
 129     uint32_t flags;
 130     uint8_t region[VHOST_USER_MAX_CONFIG_SIZE];
 131 } VhostUserConfig;
 132
 133 static VhostUserConfig c __attribute__ ((unused));
 134 #define VHOST_USER_CONFIG_HDR_SIZE (sizeof(c.offset) \
 135                                    + sizeof(c.size) \
 136                                    + sizeof(c.flags))
 137
 138 typedef struct VhostUserVringArea {
 139     uint64_t u64;
 140     uint64_t size;
 141     uint64_t offset;
 142 } VhostUserVringArea;
 143
 144 typedef struct VhostUserInflight {
 145     uint64_t mmap_size;
 146     uint64_t mmap_offset;
 147     uint16_t num_queues;
 148     uint16_t queue_size;
 149 } VhostUserInflight;
 150
 151 #if defined(_WIN32)
 152 # define VU_PACKED __attribute__((gcc_struct, packed))
 153 #else
 154 # define VU_PACKED __attribute__((packed))
 155 #endif
 156
 157 typedef struct VhostUserMsg {
 158     int request;
 159
 160 #define VHOST_USER_VERSION_MASK     (0x3)
 161 #define VHOST_USER_REPLY_MASK       (0x1 << 2)
 162 #define VHOST_USER_NEED_REPLY_MASK  (0x1 << 3)
 163     uint32_t flags;
 164     uint32_t size; /* the following payload size */
 165
 166     union {
 167 #define VHOST_USER_VRING_IDX_MASK   (0xff)
 168 #define VHOST_USER_VRING_NOFD_MASK  (0x1 << 8)
 169         uint64_t u64;
 170         struct vhost_vring_state state;
 171         struct vhost_vring_addr addr;
 172         VhostUserMemory memory;
 173         VhostUserLog log;
 174         VhostUserConfig config;
 175         VhostUserVringArea area;
 176         VhostUserInflight inflight;
 177     } payload;
 178
 179     int fds[VHOST_MEMORY_MAX_NREGIONS];
 180     int fd_num;
 181     uint8_t *data;
 182 } VU_PACKED VhostUserMsg;
 183
 184 typedef struct VuDevRegion {
 185     /* Guest Physical address. */
 186     uint64_t gpa;
 187     /* Memory region size. */
 188     uint64_t size;
 189     /* QEMU virtual address (userspace). */
 190     uint64_t qva;
 191     /* Starting offset in our mmaped space. */
 192     uint64_t mmap_offset;
 193     /* Start address of mmaped space. */
 194     uint64_t mmap_addr;
 195 } VuDevRegion;
 196
 197 typedef struct VuDev VuDev;
 198
 199 typedef uint64_t (*vu_get_features_cb) (VuDev *dev);
 200 typedef void (*vu_set_features_cb) (VuDev *dev, uint64_t features);
 201 typedef int (*vu_process_msg_cb) (VuDev *dev, VhostUserMsg *vmsg,
 202                                   int *do_reply);
 203 typedef void (*vu_queue_set_started_cb) (VuDev *dev, int qidx, bool started);
 204 typedef bool (*vu_queue_is_processed_in_order_cb) (VuDev *dev, int qidx);
 205 typedef int (*vu_get_config_cb) (VuDev *dev, uint8_t *config, uint32_t len);
 206 typedef int (*vu_set_config_cb) (VuDev *dev, const uint8_t *data,
 207                                  uint32_t offset, uint32_t size,
 208                                  uint32_t flags);
 209
 210 typedef struct VuDevIface {
 211     /* called by VHOST_USER_GET_FEATURES to get the features bitmask */
 212     vu_get_features_cb get_features;
 213     /* enable vhost implementation features */
 214     vu_set_features_cb set_features;
 215     /* get the protocol feature bitmask from the underlying vhost
 216      * implementation */
 217     vu_get_features_cb get_protocol_features;
 218     /* enable protocol features in the underlying vhost implementation. */
 219     vu_set_features_cb set_protocol_features;
 220     /* process_msg is called for each vhost-user message received */
 221     /* skip libvhost-user processing if return value != 0 */
 222     vu_process_msg_cb process_msg;
 223     /* tells when queues can be processed */
 224     vu_queue_set_started_cb queue_set_started;
 225     /*
 226      * If the queue is processed in order, in which case it will be
 227      * resumed to vring.used->idx. This can help to support resuming
 228      * on unmanaged exit/crash.
 229      */
 230     vu_queue_is_processed_in_order_cb queue_is_processed_in_order;
 231     /* get the config space of the device */
 232     vu_get_config_cb get_config;
 233     /* set the config space of the device */
 234     vu_set_config_cb set_config;
 235 } VuDevIface;
 236
 237 typedef void (*vu_queue_handler_cb) (VuDev *dev, int qidx);
 238
 239 typedef struct VuRing {
 240     unsigned int num;
 241     struct vring_desc *desc;
 242     struct vring_avail *avail;
 243     struct vring_used *used;
 244     uint64_t log_guest_addr;
 245     uint32_t flags;
 246 } VuRing;
 247
 248 typedef struct VuDescStateSplit {
 249     /* Indicate whether this descriptor is inflight or not.
 250      * Only available for head-descriptor. */
 251     uint8_t inflight;
 252
 253     /* Padding */
 254     uint8_t padding[5];
 255
 256     /* Maintain a list for the last batch of used descriptors.
 257      * Only available when batching is used for submitting */
 258     uint16_t next;
 259
 260     /* Used to preserve the order of fetching available descriptors.
 261      * Only available for head-descriptor. */
 262     uint64_t counter;
 263 } VuDescStateSplit;
 264
 265 typedef struct VuVirtqInflight {
 266     /* The feature flags of this region. Now it's initialized to 0. */
 267     uint64_t features;
 268
 269     /* The version of this region. It's 1 currently.
 270      * Zero value indicates a vm reset happened. */
 271     uint16_t version;
 272
 273     /* The size of VuDescStateSplit array. It's equal to the virtqueue
 274      * size. Slave could get it from queue size field of VhostUserInflight. */
 275     uint16_t desc_num;
 276
 277     /* The head of list that track the last batch of used descriptors. */
 278     uint16_t last_batch_head;
 279
 280     /* Storing the idx value of used ring */
 281     uint16_t used_idx;
 282
 283     /* Used to track the state of each descriptor in descriptor table */
 284     VuDescStateSplit desc[0];
 285 } VuVirtqInflight;
 286
 287 typedef struct VuVirtqInflightDesc {
 288     uint16_t index;
 289     uint64_t counter;
 290 } VuVirtqInflightDesc;
 291
 292 typedef struct VuVirtq {
 293     VuRing vring;
 294
 295     VuVirtqInflight *inflight;
 296
 297     VuVirtqInflightDesc *resubmit_list;
 298
 299     uint16_t resubmit_num;
 300
 301     uint64_t counter;
 302
 303     /* Next head to pop */
 304     uint16_t last_avail_idx;
 305
 306     /* Last avail_idx read from VQ. */
 307     uint16_t shadow_avail_idx;
 308
 309     uint16_t used_idx;
 310
 311     /* Last used index value we have signalled on */
 312     uint16_t signalled_used;
 313
 314     /* Last used index value we have signalled on */
 315     bool signalled_used_valid;
 316
 317     /* Notification enabled? */
 318     bool notification;
 319
 320     int inuse;
 321
 322     vu_queue_handler_cb handler;
 323
 324     int call_fd;
 325     int kick_fd;
 326     int err_fd;
 327     unsigned int enable;
 328     bool started;
 329 } VuVirtq;
 330
 331 enum VuWatchCondtion {
 332     VU_WATCH_IN = POLLIN,
 333     VU_WATCH_OUT = POLLOUT,
 334     VU_WATCH_PRI = POLLPRI,
 335     VU_WATCH_ERR = POLLERR,
 336     VU_WATCH_HUP = POLLHUP,
 337 };
 338
 339 typedef void (*vu_panic_cb) (VuDev *dev, const char *err);
 340 typedef void (*vu_watch_cb) (VuDev *dev, int condition, void *data);
 341 typedef void (*vu_set_watch_cb) (VuDev *dev, int fd, int condition,
 342                                  vu_watch_cb cb, void *data);
 343 typedef void (*vu_remove_watch_cb) (VuDev *dev, int fd);
 344
 345 typedef struct VuDevInflightInfo {
 346     int fd;
 347     void *addr;
 348     uint64_t size;
 349 } VuDevInflightInfo;
 350
 351 struct VuDev {
 352     int sock;
 353     uint32_t nregions;
 354     VuDevRegion regions[VHOST_MEMORY_MAX_NREGIONS];
 355     VuVirtq vq[VHOST_MAX_NR_VIRTQUEUE];
 356     VuDevInflightInfo inflight_info;
 357     int log_call_fd;
 358     int slave_fd;
 359     uint64_t log_size;
 360     uint8_t *log_table;
 361     uint64_t features;
 362     uint64_t protocol_features;
 363     bool broken;
 364
 365     /* @set_watch: add or update the given fd to the watch set,
 366      * call cb when condition is met */
 367     vu_set_watch_cb set_watch;
 368
 369     /* @remove_watch: remove the given fd from the watch set */
 370     vu_remove_watch_cb remove_watch;
 371
 372     /* @panic: encountered an unrecoverable error, you may try to
 373      * re-initialize */
 374     vu_panic_cb panic;
 375     const VuDevIface *iface;
 376
 377     /* Postcopy data */
 378     int postcopy_ufd;
 379     bool postcopy_listening;
 380 };
 381
 382 typedef struct VuVirtqElement {
 383     unsigned int index;
 384     unsigned int out_num;
 385     unsigned int in_num;
 386     struct iovec *in_sg;
 387     struct iovec *out_sg;
 388 } VuVirtqElement;
 389
 390 /**
 391  * vu_init:
 392  * @dev: a VuDev context
 393  * @socket: the socket connected to vhost-user master
 394  * @panic: a panic callback
 395  * @set_watch: a set_watch callback
 396  * @remove_watch: a remove_watch callback
 397  * @iface: a VuDevIface structure with vhost-user device callbacks
 398  *
 399  * Intializes a VuDev vhost-user context.
 400  **/
 401 void vu_init(VuDev *dev,
 402              int socket,
 403              vu_panic_cb panic,
 404              vu_set_watch_cb set_watch,
 405              vu_remove_watch_cb remove_watch,
 406              const VuDevIface *iface);
 407
 408
 409 /**
 410  * vu_deinit:
 411  * @dev: a VuDev context
 412  *
 413  * Cleans up the VuDev context
 414  */
 415 void vu_deinit(VuDev *dev);
 416
 417 /**
 418  * vu_dispatch:
 419  * @dev: a VuDev context
 420  *
 421  * Process one vhost-user message.
 422  *
 423  * Returns: TRUE on success, FALSE on failure.
 424  */
 425 bool vu_dispatch(VuDev *dev);
 426
 427 /**
 428  * vu_gpa_to_va:
 429  * @dev: a VuDev context
 430  * @plen: guest memory size
 431  * @guest_addr: guest address
 432  *
 433  * Translate a guest address to a pointer. Returns NULL on failure.
 434  */
 435 void *vu_gpa_to_va(VuDev *dev, uint64_t *plen, uint64_t guest_addr);
 436
 437 /**
 438  * vu_get_queue:
 439  * @dev: a VuDev context
 440  * @qidx: queue index
 441  *
 442  * Returns the queue number @qidx.
 443  */
 444 VuVirtq *vu_get_queue(VuDev *dev, int qidx);
 445
 446 /**
 447  * vu_set_queue_handler:
 448  * @dev: a VuDev context
 449  * @vq: a VuVirtq queue
 450  * @handler: the queue handler callback
 451  *
 452  * Set the queue handler. This function may be called several times
 453  * for the same queue. If called with NULL @handler, the handler is
 454  * removed.
 455  */
 456 void vu_set_queue_handler(VuDev *dev, VuVirtq *vq,
 457                           vu_queue_handler_cb handler);
 458
 459 /**
 460  * vu_set_queue_host_notifier:
 461  * @dev: a VuDev context
 462  * @vq: a VuVirtq queue
 463  * @fd: a file descriptor
 464  * @size: host page size
 465  * @offset: notifier offset in @fd file
 466  *
 467  * Set queue's host notifier. This function may be called several
 468  * times for the same queue. If called with -1 @fd, the notifier
 469  * is removed.
 470  */
 471 bool vu_set_queue_host_notifier(VuDev *dev, VuVirtq *vq, int fd,
 472                                 int size, int offset);
 473
 474 /**
 475  * vu_queue_set_notification:
 476  * @dev: a VuDev context
 477  * @vq: a VuVirtq queue
 478  * @enable: state
 479  *
 480  * Set whether the queue notifies (via event index or interrupt)
 481  */
 482 void vu_queue_set_notification(VuDev *dev, VuVirtq *vq, int enable);
 483
 484 /**
 485  * vu_queue_enabled:
 486  * @dev: a VuDev context
 487  * @vq: a VuVirtq queue
 488  *
 489  * Returns: whether the queue is enabled.
 490  */
 491 bool vu_queue_enabled(VuDev *dev, VuVirtq *vq);
 492
 493 /**
 494  * vu_queue_started:
 495  * @dev: a VuDev context
 496  * @vq: a VuVirtq queue
 497  *
 498  * Returns: whether the queue is started.
 499  */
 500 bool vu_queue_started(const VuDev *dev, const VuVirtq *vq);
 501
 502 /**
 503  * vu_queue_empty:
 504  * @dev: a VuDev context
 505  * @vq: a VuVirtq queue
 506  *
 507  * Returns: true if the queue is empty or not ready.
 508  */
 509 bool vu_queue_empty(VuDev *dev, VuVirtq *vq);
 510
 511 /**
 512  * vu_queue_notify:
 513  * @dev: a VuDev context
 514  * @vq: a VuVirtq queue
 515  *
 516  * Request to notify the queue via callfd (skipped if unnecessary)
 517  */
 518 void vu_queue_notify(VuDev *dev, VuVirtq *vq);
 519
 520 /**
 521  * vu_queue_pop:
 522  * @dev: a VuDev context
 523  * @vq: a VuVirtq queue
 524  * @sz: the size of struct to return (must be >= VuVirtqElement)
 525  *
 526  * Returns: a VuVirtqElement filled from the queue or NULL. The
 527  * returned element must be free()-d by the caller.
 528  */
 529 void *vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz);
 530
 531
 532 /**
 533  * vu_queue_unpop:
 534  * @dev: a VuDev context
 535  * @vq: a VuVirtq queue
 536  * @elem: The #VuVirtqElement
 537  * @len: number of bytes written
 538  *
 539  * Pretend the most recent element wasn't popped from the virtqueue.  The next
 540  * call to vu_queue_pop() will refetch the element.
 541  */
 542 void vu_queue_unpop(VuDev *dev, VuVirtq *vq, VuVirtqElement *elem,
 543                     size_t len);
 544
 545 /**
 546  * vu_queue_rewind:
 547  * @dev: a VuDev context
 548  * @vq: a VuVirtq queue
 549  * @num: number of elements to push back
 550  *
 551  * Pretend that elements weren't popped from the virtqueue.  The next
 552  * virtqueue_pop() will refetch the oldest element.
 553  *
 554  * Returns: true on success, false if @num is greater than the number of in use
 555  * elements.
 556  */
 557 bool vu_queue_rewind(VuDev *dev, VuVirtq *vq, unsigned int num);
 558
 559 /**
 560  * vu_queue_fill:
 561  * @dev: a VuDev context
 562  * @vq: a VuVirtq queue
 563  * @elem: a VuVirtqElement
 564  * @len: length in bytes to write
 565  * @idx: optional offset for the used ring index (0 in general)
 566  *
 567  * Fill the used ring with @elem element.
 568  */
 569 void vu_queue_fill(VuDev *dev, VuVirtq *vq,
 570                    const VuVirtqElement *elem,
 571                    unsigned int len, unsigned int idx);
 572
 573 /**
 574  * vu_queue_push:
 575  * @dev: a VuDev context
 576  * @vq: a VuVirtq queue
 577  * @elem: a VuVirtqElement
 578  * @len: length in bytes to write
 579  *
 580  * Helper that combines vu_queue_fill() with a vu_queue_flush().
 581  */
 582 void vu_queue_push(VuDev *dev, VuVirtq *vq,
 583                    const VuVirtqElement *elem, unsigned int len);
 584
 585 /**
 586  * vu_queue_flush:
 587  * @dev: a VuDev context
 588  * @vq: a VuVirtq queue
 589  * @num: number of elements to flush
 590  *
 591  * Mark the last number of elements as done (used.idx is updated by
 592  * num elements).
 593 */
 594 void vu_queue_flush(VuDev *dev, VuVirtq *vq, unsigned int num);
 595
 596 /**
 597  * vu_queue_get_avail_bytes:
 598  * @dev: a VuDev context
 599  * @vq: a VuVirtq queue
 600  * @in_bytes: in bytes
 601  * @out_bytes: out bytes
 602  * @max_in_bytes: stop counting after max_in_bytes
 603  * @max_out_bytes: stop counting after max_out_bytes
 604  *
 605  * Count the number of available bytes, up to max_in_bytes/max_out_bytes.
 606  */
 607 void vu_queue_get_avail_bytes(VuDev *vdev, VuVirtq *vq, unsigned int *in_bytes,
 608                               unsigned int *out_bytes,
 609                               unsigned max_in_bytes, unsigned max_out_bytes);
 610
 611 /**
 612  * vu_queue_avail_bytes:
 613  * @dev: a VuDev context
 614  * @vq: a VuVirtq queue
 615  * @in_bytes: expected in bytes
 616  * @out_bytes: expected out bytes
 617  *
 618  * Returns: true if in_bytes <= in_total && out_bytes <= out_total
 619  */
 620 bool vu_queue_avail_bytes(VuDev *dev, VuVirtq *vq, unsigned int in_bytes,
 621                           unsigned int out_bytes);
 622
 623 #endif /* LIBVHOST_USER_H */